7075 T6 aluminum alloys are applied in aircraft construction. The success of their weldability is a technological challenge bringing advantages in the lightening of structures. This work was carried out in the aim to analyze the mechanical behavior and microstructural evolution of aluminum alloys 7075 T6 sheets welded by TIG process, by applying a pulsed current. A notable microstructural change occurred in our materials by the thermal effect, resulting in degradation of mechanical properties. The break of samples is privileged in the connecting region, which is characterized by a columnar structure, contributing to reduce the ability of the material to deforme plastically.